Telephone-answering machines with upright head positioning

ABSTRACT

The specification describes a telephone-answering machine, not adapted to record a call, in which the disc carrying the magnetic recording material, a disc for indicating the elapse of available recording time, and other rotary parts are mounted in a single cast frame which in turn is mounted on a chassis.

United States Patent Appl. No. Filed Patented Assignee TELEPHONE-ANSWERING MACHINES WITH UPRIGHT HEAD POSITIONING 12 Claims, 14 Drawing Figs.

u.s. c1 179/6 R, 179/1002 M1, 179/1002 CA 1111.01 ..G1lb 21/08, 01 lb 21/24, 1104111 1/64 Field 61 sw ll 179/6 AC, 100.2 c, 100.2 CA, 1002 P, 100.2 s, 274/4 A, 4.1,

11 A; 340/1741 F, 174.1 12; 346/74 MC; 200/1 1 References Cited UNITED STATES PATENTS Smith Muller et a1.

Ricketts Kolm Salzberg et al... Zimmer Droniou et 31...

Ward

Klein et a1 Primary ExaminerStanley M. Urynowicz, Jr. Assistant Examiner-Raymond F. Cardillo, .lr. Att0rneySemmes and Semmes 200/11 X 179/6 179/1002 179/1002 X 179/6 340/174.1 200/11 X 179/1002 179/1002 X ABSTRACT: The specification describes a telephone-answering machine, not adapted to record a call, in which the disc carrying the magnetic recording material, a disc for indicating the elapse of available recording time, and other rotary parts are mounted in a single cast frame which in turn is mounted on D, 24, 28 a chassis.

20 m I] Q I 0 -I8 31 O Q II 33 g PATENTED AUG 31971 SHEET 1 OF 7 PAIENTED me sen :3, 597', 545

SHEU 2 (IF 7 no g aw semmesandsemmes PATENTED AUG 3 1971 3555871545};

sum a GP 7 semmesandsemmes PATENTEUAUG am: 3597545 SHEET 5 OF 7 5% semmesandsemmes PATENTEB AUG 3191:

Fig. 14

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SHEET 7 0F 7 m WM I TELEPHONE-ANSWERING MACHINES WITH UIPRIGHT- HEAD POSlTKONING The present invention relates to automatic telephone-answering machines, more particularly to such machines which i are not adapted to record a message from a caller.

Known telephone-answering machines of the type without any facility for recording a message from a caller usually have an operation selection switch with three settings, one for recording a message to be played over to the caller, another for playing back the message for checking it, and a third in which the telephone answering machine is connected with the telephone lines ready to respond to a call. in the third operational state the machine is started by the ringing current supplied via the telephone lines and the message recorded by the subscriber possessing the answering machine is played over to the caller. The message may be recorded, for instance, on a magnetic disc. After the message hasbeen played over, the operational cycle started by the ringing current comes to an end and the answering machine returns to a ready position for receiving the next call.

One object of the present invention is to provide a telephone-answering machine of this type which on the one hand is simple and compact in construction and on the other hand is particularly reliable in operation.

A further object of the invention is to provide such a telephone-answering machine whose components, particularly drive means, magnetic sound-recording means, and switching means can be readily adapted for the construction of a telephone-answering machine capable of recording a message from a caller after the caller has heard the message recorded by the subscriber possessing the telephone-answering machine. Such telephone-answering machines capable of recording a message from a caller may be of the fixed time type in which the recording time of a message is fixed or the time may be variable. A particular object of the present invention is to provide a manufacturer of such telephone-answering machines with a basic, noncall-recording, type of machine which can be readily adapted for use for recording calls.

A further object of the present invention is to provide a telephone-answering machine which is improved as regards simplicity and cheapness of servicing.

in accordance with one aspect the present invention consists in a telephone-answering machine comprising: a housing; a chassis in the housing; a magnetic recording device adapted to record a message and play it back to a telephone caller; mechanical drive means for the recording device; selective switching means for setting the apparatus in anyone of the following operational conditions: (i) recording of a message, (ii) playback of the message for checking, and (iii) telephone operation with playback of the message in response to a call; and timing means for controlling the apparatus during at least one of the operational states; a frame, the magnetic recording device, the drive means, and the timing means being mounted on the frame so as to form a single subassembly.

Preferably the frame is a casting and is mounted on the chassis of the apparatus while the subassembly comprises first, second and third shafts mounted in the frame with an interference fit; a drive motor with a drive shaft; a disc-shaped magnetic recording medium carrier joumaled on the first shaft, the carrier being adapted to be driven by frictional contact at its periphery; magnetic recording medium mounted on the carrier; a pivoting lever; a large frictional wheel and a small frictional wheel, a shaft on which the large and small frictional wheels are mounted, this shaft beingjournaled in the pivoting lever; a solenoid for moving the pivoting lever and the large and small frictional wheels between an idle position, and a position in which the small frictional wheel makes peripheral contact with the periphery of the magnetic recording medium carrier and the large frictional wheel makes peripheral contact with the shaft of the motor, an indicator disc; peripheral markings in the form ofa scale on the indicator disc, an opening being provided in the housing for viewing the scale, the scale indicating the course of a cycle of operation of the telephone-answering machine; a rotary timing disc; metallic contact tracks on the disc, stationary brush means for making contact with the tracks for closing and opening electrical contact paths on operation of the timing disc, the timing disc being connected with the indicator disc for rotation with it about a common axis at the same speed; and stepdown toothed gearing for causing the indicator disc to rotate with the magnetic recording medium carrier but at a lower speed.

in accordance with a further preferred feature of the invention the ratio of the stepdown toothed gearing is such that for a number of revolutions of the magnetic recording medium carrier corresponding to playback from all available storage capacity of the magnetic recording medium the indicator disc makes substantially one single revolution. The magnetic recording medium can be in the form of a circular sheet of foil and the magnetic recording medium carrier can have a resilient surface covering on which the magnetic recording medium rests loosely. The resilient covering of the magnetic recording medium carrier can stop short of a central part of the carrier.

The invention also consists in a magnetic recording medium carrier which comprises: a hub joumaled on a first shaft; a radial turntable fixed on the hub; and the resilient covering extending partially over the turntable. The hub can be provided with a flange, the radial turntable being fixed on the undersurface of this flange, some of the resilient material covering being on top of the turntable and having an upper surface substantially flush with a top surface of the flange. The carrier can be provided with releasable means for holding the central part of the magnetic recording medium down against the flange, an annular recess surrounding the flange so as to leave the surface of the turntable free.

The invention also resides in a magnetic head which is arranged to cooperate with a magnetic recording medium and is preferably arranged substantially opposite a drive engagement on the periphery ofa carrier comprises a turntable covered on its undersurface by the resilient covering as well as on its top surface and at the periphery of the surfacing material can form a frictional driving track.-

In accordance with a further preferred aspect of the invention the telephone-answering machine comprises a rotary timing disc of insulating material carrying concentrically arranged conducting tracks, brush means for engaging the tracks, the tracks having electrically inactive interruptions, and islands of metallic surfacing material in the interruptions to provide abutments for the brush means. The metallic sur facing material of the islands is preferably at the same level as adjacent track surface and the brush means have blunt ends arranged to bridge over gaps between the islands and adjacent track material in order not to damage the insulating material of the timing disc. The brush means can for instance be made of lengths of wire with curved ends. The insulating material of the disc can be glass fiber-reinforced material. The tracks on it can be made using a printed circuit technique.

The invention also resides in a magnetic head which is carried by means of a forked part which in turn is carried by two parallel generally horizontal struts whose ends make hinge joints with the part carrying the magnetic head. At their opposite ends the struts can be connected with an adjustable part by means of hinge joints so that a parallelogram linkage is formed. In order to urge the recording head towards the recording medium a generally diagonal tension spring extends across the parallelogram linkage. The part at the ends of the struts remote from the magnetic recording head can be in the form ofa lug whose position can be changed by bending. For instance, the lug can be connected with a piece of sheet metal by means of a narrow connecting part. In order to guide vertical movement of the magnetic head use can be made of a vertical part with a vertical slot.

One telephone-answering machine in accordance with the invention is now described with reference to the accompanying drawings.

FIG. 1 is a perspective view of the telephone answering machine in accordance with the invention seen as a whole.

FIG. 2 is a plan view of the chassis ofthe answering machine removed from its housing.

FIG. 3 is a section through the combined magnetic recording, drive and control switching unit of the telephone-answering machine in accordance with the invention.

FIGS. 4 to 7 show details of the construction of the brush contact control switching unit forming part of the telephoneanswering machine in accordance with the invention.

FIGS. 8 to 12 show details of the adjustable magnetic head unit forming part of the telephone-answering machine in accordance with the invention.

FIG. 13 is a simplified circuit diagram of the telephone-answering machine in accordance with the invention.

FIG. 14 is a diagram to illustrate the actuation of the individual switching contacts of the control switching unit during the course of an operating cycle of the telephone-answering machine in accordance with the invention.

The following particular description of the telephone-answering machine shown in the drawings is divided into sections as follows.

EXTERNAL FEATURES OF THE TELEPHONE ANSWERING MACHINE FIG. 1 shows the telephone-answering machine in a general perspective view. The machine is accommodated in a rectangular housing 1 made of any suitable material. For example the housing can be made of wood so as to meet certain aesthetic standards. The front of the housing is formed by a plate 2 on which operating and indicating means are provided. These means include a line or mainswitch 3 for switching the machine on and off as a whole; a window 4 showing the periphery of a rotating disc with a time scale 5 divided up into seconds so as to indicate the course of operation of the machine to the user. The disc is shown in detail in FIG. 3, where it is indicated by reference numeral 22. In the machine described in the present s ecification, the operating cycle corresponds with one rotation of the disc and the scale amounts to 60 seconds. Reference numeral 6 indicates a socket for the connection ofa microphone lead for recording a message. The microphone can also be used as a loudspeaker for playing back the message for checking purposes. Reference numeral 7 denotes a knob of a selection switch for setting the answering machine in anyone of three different operational states. The position of the knob 7 is denoted by reference characters a, b and c mounted on the front plate for cooperation with an index mark 8 on the knob. The characters a, b and 0 respectively indicate: message record; message playback; and telephone operation. In the last-named operational state the machine is connected with the telephone line ready to play the message to any caller who rings up the subscriber using the answering machine.

INTERNAL CONSTRUCTIONAL FEATURES OF THE ANSWERING MACHINE FIG. 2 generally shows the interior of the answering machine.

General reference numeral 10 denotes a recording unit or subassembly which itself is made up of a magnetic recording device. a drive means, and a timing disc unit to be described in detail below. The subassembly 10 is mounted on the chassis 9. On the right-hand part of the chassis nonmechanical electrical components are mounted as denoted by general reference numeral 11. At the front and rear the chassis 9 has upwardly extending flanges 9a, 9b perpendicular to the rest ofit. The front flange 9a has the line switch 3 mounted in it while on the right the switch 12 is mounted, its operating shaft being indicated by reference numeral 12a. The knob 7 (as shown in FIG. 1) is mounted on this shaft for operating the switch 12. A line flex 13 extends out through a grommet 14 in the rear chassis flange 9b. Reference numeral 15 indicates an externally accessible fuse. On the right-hand side at the rear the telephone connection 16 can be seen.

On the right-hand side to the rear the line transformer 17 can be seen. Further to the right there is a vertical plate 18 on which electronic components constituting the amplifying and other circuits are mounted. There is a further vertical circuit plate 19 on which components such as relays, condensers and the like are arranged. The electrical and electronic circuitry is conventional and will be further described below in connection with the description of the function of the telephone-answering machine.

As shown in the plan view of FIG. 2, the recording subassembly 10 includes a cast frame 20 fixed to the chassis 9 and supporting a disc-shaped magnetic recording medium carrier 21 under which there is the disc 22 of the control switching unit. The disc 22 and the carrier 21 are mounted on shafts which can be rotated in relation to each other. A drive motor 23 is also mounted on the cast frame 20 and serves for rotating drive means or gearing to be described and operating the switching unit. The output or drive shaft 24 of the motor can be brought into frictional engagement with the large friction wheel 25 ofa friction wheel stepdown drive generally denoted by reference numeral 25 (see FIG. 3). The output wheel (which is not shown in FIG. 2) of this drive 25 is brought into engagement with the periphery of the magnetic recording medium carrier 21 when the large wheel 25 is brought into frictional engagement with the motor output shaft 24. The drive 25' is mounted on the frame 20 by means of a pivoting lever 26 so that it can pivot between, on the one hand, a rest position in which the large friction wheel 25 is out of engagement with the motor output shaft 24 and the small output friction wheel of the drive 25 is out of engagement with the magnetic medium carrier 21, and, on the other hand, the drive position in which the large and small friction wheels of the drive 25' are in frictional engagement with the motor output shaft 24 and the magnetic recording medium carrier 21 so that the latter can be driven by the motor. The pivotal movement of the drive 25 is brought about by means of a solenoid 27 which is fixed to the cast frame 20. Its moving part or arma ture 28 is connected by means ofa spring 29 with the pivoting lever 26 in which the parts of the drive 25' are journaled. The arrangement is such that on energization of the solenoid 27 and the consequent attraction of the armature, the friction wheel drive 25' is moved into its engagement position.

Reference numeral 30 denotes an erase head capable of sweeping the whole of the recording area of the recording medium arranged on the carrier 21, when the latter is rotated, so that a single rotation of the magnetic recording medium carrier 21 serves for the erasure of the whole recording.

Reference numeral 31 generally denotes a holding means for a magnetic recording head 32 which serves for recording the message on the magnetic recording medium arranged on the carrier 21. The holding means 31 is arranged to pivot as a whole with the vertical pin 33. Such pivoting is brought about by means of a cam control means as described below. The pivoting causes the magnetic recording head 32 to move approximately radially in relation to the carrier 21 during recording or playback so that recording or playback occurs along a spiral track on the magnetic recording medium.

On the outer periphery of the disc 22 there is the previously mentioned scale 5 for indicating the course of operation of the machine. The scale can be viewed through an opening in the front-chassis flange 9a and the above-mentioned window 4 in the front plate 2 of the machine.

Further features of the telephone-answering machine will be gathered from the sectional view of FIG. 3. The cast frame 20 fixed to the chassis has three shafts 34, 35 and 36 mounted in it with an interference fit. The magnetic recording medium carrier 21 is journaled on the shaft 24. On its upper surface the carrier supports the magnetic recording medium 21a which is in the form of foil and cooperates with the magnetic head 32.

On the shaft 36 the disc 22 is journaled. Below disc 22 I provide a timing disc 37 carrying contact tracks arranged for cooperation with a set 38 of 16 brushes 40. The disc 37 and the brushes 40 form the timing means of the telephone-answering machine. The brushes which are individually denoted by reference numeral 40, cooperate with the contact tracks on timing disc 37.

On the shaft 35 there is a coaxial gear and pinion pair whose gear is driven by the gear teeth on the hub of the carrier 21 and whose pinion engages gear teeth inside the peripheral flange of the disc 22. The gear pinion pair 4! acts as a stepdown gearing so that one revolution of the disc 22 corresponds with I6 revolutions of the carrier 21. This is because the magnetic recording head 32 moves along a spiral path over the magnetic recording medium 21:: corresponding to 16 revolutions ofthe carrier. During revolution of the disc 37, the

tracks on it cooperate with the brushes 40 in opening and closing electrical circuits in accordance with a cycle ofoperations.

The prime mover is the motor 23 whose output shaft 24 drives the large wheel 25 of stepdown drive 25' providing that the solenoid 27 is energized so as to bring them into frictional engagement; the small output wheel of the drive 25 engages the outer periphery of the carrier 21. The friction drive 25 is arranged for pivoting movement as has already been described in connection with FIG. 2. This pivoting means includes the pivoting lever 26 which can be moved by the solenoid 27 (see FIG. 2) from the rest position in which there is no frictional engagement with the motor shaft 24 and the disc 22, and the drive position as shown in FIG. 3.

Reference numeral 43 denotes a cam which is fixed on the hub of the disc 22. The cam, which has a spiral engagement surface, brings about radial swinging movement of the magnetic head 32 in relation to the carrier 21 and the magnetic recording medium 210. The follower engaging the cam will be described below with reference to FIG. 8.

THE MAGNETIC RECORDING MEDIUM CARRIER As shown in detail of FIG. 3, the carrier 21 has a hub 42 journaled on the shaft 34. The hub has a flange 44 whose upper surface serves to support the inner part of the magnetic recording medium 210 in the form ofa round piece of foil. On the lower side of the flange 44 a sheet metal turntable 45 is attached whose diameter corresponds approximately to the diameter of the magnetic recording medium 21a. The sheet metal turntable 45 has vulcanized on it a silicone rubber covering 46. This covering extends over an annular area of the turntable which corresponds to the range of radial movement of the recording head 32. In the arrangement shown, the covering 46 extends from a position removed from the outer edge of the flange 44 radially outwards over the top surface of the turntable, down around the edge of the turntablev and then towards the axis of the turntable underneath it. The peripheral portion of the covering is cylindrical and serves as a friction surface for engagement with the small output wheel of the drive 25.

The recording medium 21a is mounted loosely upon the carrier 21 in such a manner that its inner edge lies on the upper side of the flange 44 of the hub part 42 while its outer part lies on the top surface of the silicone rubber covering 46. In order to prevent relative rotation between the recording medium 21a and the carrier I provide a retaining plate 47 which is held down by three screws 48 on to the flange 44 of the hub 42 so as to clamp the recording medium 21a in position.

In its outer part, which is used for recording, the magnetic recording medium 210 lies loosely on the silicone rubber covering 46. This loose arrangement on a yielding elastic underlay insures that the magnetic recording medium can give slightly under the pressure of the recording head and therefore there is always a satisfactory engagement of the magnetic recording head on the recording medium. A further advantage of the construction in accordance with the invention is a shock absorbing effect of the selected manner in which the magnetic recording medium is supported. Mechanical vibrations of the magnetic recording medium carrier 21, which are transmitted from outside or may be due for example to slide irregularities in the manner in its bearing means, are strongly attenuated by the damping effect of the silicone rubber covering 46.

A further advantage of the construction in accordance with the invention is the simplicity with which the recording medium 2la can be replaced on servicing. It is only necessary to remove the screws 48 to enable the recording medium to be rapidly removed and replaced.

As is apparent, the silicone rubber covering 46 extends in a radial direction inwards not quite as far as the outer periphery of the flange 44 so that a certain annular gap 49 is left between the flange 44 and the innermost limit of the rubber covering 46. The provision of this gap has the advantage that any slight differences in level between the upper surface of the flange 44 and the upper surface of the silicone rubber covering 46 do not constitute a step which might have a disadvantageous effect on the supporting of the recording medium 210. Instead any such differences in level will be smoothly passed over by the part ofthe recording medium 210 extending over the gap.

The silicone rubber covering 46 extends in a radial direction only slightly beyond the edge of the recording medium 21a. It extends slightly beyond the edge of the turntable 45 in order to form an annular part for engagementby the drive 25. The position at which the drive 25 makes an engagement with the periphery of the covering 46 is approximately diametrically opposite the magnetic recording head 32 so that any slight deformation of the silicone rubber covering does not have any substantial influence on the operation of the magnetic recording head 32.

THE TIMING DISC CARRYING CONTACT TRACKS In what follows the disc 37 carrying contact tracks and the cooperating brush set 38, (see FIG. 3) will be described with reference to FIGS. 4 to 7.

FIG. 4 is a perspective view showing diagrammatically the operation of the timing track disc 37. The disc is made of an insulating material, for example an epoxy resin reinforced with glass fiber. On its lower surface contact tracks are arranged. The tracks are made, for example, by a technique as used for making printed circuits and involving photomechanical reproduction from a master. In FIG. 4 only one doublecontact track 50 is shown which cooperates with two contacting brushes 40. Over the greater part of its periphery the contact track 50 is free of any interruption so that the two brushes of the pair 40 are connected together electrically by the track. In the angular range denoted by a' the part of the track 50 corresponding to the right-hand brush is discontinuous and there is a track section 51 which is insulated from the rest of the track 50 by a small gap 52. During the time in which the track section 51 makes contact with one of the brushes 40, the two brushes are insulated from one another and this is employed for bringing about a switching function in the telephone-answering machine.

While in the case of prior art timing track discs for switching purposes the interrupting part to be contacted by a brush is merely a notch of exposed insulating material of which the disc is made, in accordance with the invention the interrupting part has an island 51 which is insulated from the rest of the track 50 by the narrow gap or slit 52. With this arrangement the disadvantage of known apparatus is avoided, that is to say the wear on the exposed material of the disc due to the abrasive action of the brush, and the consequent lack of reliability and reduction in service life.

FIG. 5 is a further diagrammatic view of the timing disc as shown in FIG. 4 from the side so as to indicate the track island 51. The brushes are mounted in a holding means 21.

In order to accommodate as may contact brushes as possible alongside one another, the brushes are not constructed as strip springs but are made of wire material. The contact heads making engagement with the conducting tracks can be constructed in a conventional manner, though in the embodiment shown no special contact projections or knobs are provided and as shown the contact brushes are simply bent at their front ends as indicated by reference numeral 53. The radius of the contact heads, that is to say the radius of curvature of the spring wire at a position adjacent to the contact position on the disc must be suitably chosen in relation to the insulating gaps 52 to insure that the contact brushes rest on the conducting material substantially the whole time and wear of the material of the disc 37 is effectively prevented in the gaps 52.

The insulation clearance or gap 52 extending over the disc should be made comparatively small, the limiting factor being the voltage existing between adjacent tracks. The brushes are preferably made of drawn beryllium-copper wire. The ends of the brushes can be bent to shape before or after heat treatment of the wire. The ends can be ground to shape.

The disc 37 of FIG. 3 is shown from below in FIG. 6 (in accordance with the direction of the arrow VI in FIG. 3) the diameter is 9 cm. FIG. 6 shows the various contact tracks for the 16 contact brushes which are arranged in groups.

THE ADJUSTABLE MOUNTING MEANS FOR THE MAGNETIC SOUND HEAD The following description refers more particularly to FIGS. 8 to 12. As can be seen from the plan view of FIG. 9, the mounting means can be used for two magnetic sound heads 32 and 32'. However, the use of two or more such sound heads mounted side by side is only illustrated as a hint to those skilled in the art that such an adaptation is possible if it is desired to redesign the specific embodiment of the invention described and illustrated in the drawings. In the embodiment specifically under consideration, only a single magnetic sound head 32 is required for recording the message to be played back and for the playing-back of the message, as can be seen from the plan view of FIG. 2. The following description is equally appropriate for a twin magnetic head arrangement as is shown inFIGS. 9, 10 and 11 and for a single magnetic recording head arrangement as shown in FIGS. 8 and 12.

The whole holding means 31 is mounted on the horizontal plate 31' which is fixed to a vertical pin 33 mounted in the chassis 9 in a bearing so that it can rotate about its axis. The pin 33 is provided with a follower arm 43a which cooperates with the cam 43 (see also FIG. 3). Rotation of the cam causes the plate 31' to be swung so that the corresponding arcuate movement of the magnetic head 32 carried by it can be described as a substantially radial movement in relation to the carrier 21. This movement proceeds with substantially the same speed across the face of the magnetic recording medium.

The adjustable mounting means for the sound head 32 comprises the open-ended resilient clamping means 54 in which the sound head is held, for example by means of a resilient clamping action. As its front end face the part 54 carries a locating pin which fits in a corresponding vertical guide slot 56 in the front upwardly bent end part 57 of the plate 31' (see FIG. 8 and the front view of FIG. 11). The locating pin 55 can slide vertically in the slot 56.

At the opposite end of the plate 31 there is an upright plate part 58 which is held in place by means ofa screw 59 as shown in FIG. 9. The plate part 58 carries a lug 60 which is substantially perpendicular to it so as to be parallel to the part 57. The lug 60 is carried on the upright plate retainer 58 by means of a narrow connecting part 61 and is stamped from the same piece of sheet metal as the plate part 58. The sheet metal is of such a thickness that it can be comparatively easily bent by grasping the mounting means with the hand. The lug 60 has lower and upper slots 62 and 63 which are given a T-shape, see FIG. 10. The clamping means 54 is provided on its rear edge with corresponding notches 64 and 65. Between the forked part 54 and the lug 60 mounted on the part 58 there are two substantially parallel struts 66 and 67 which are generally parallel to the surface of the carrier 21. The ends of the struts, which are sharp so as to provide fulcrums, are fitted in the notches 64 and 65 and in the slots 62 and 63. The parts 68 and 69 (see FIG. 8) fitting into the slots 62 and 63 of the lug 60 are of reduced width. These parts of reduced width are provided with central slots 70 as shown in FIG. 12.

The structure consisting of the lug 60, the two struts 66 and 67 and the clamping means 54 with the magnetic head constitutes a rectangle which is loaded by a generally diagonal spring 71, see FIG. 8, so that the magnetic head is urged downwards resiliently. The struts form a parallelogram linkage so that when it moves vertically the magnetic head remains parallel to itself. As will be familiar to those in the art, the parallelogram linkage causes the tension force exerted by the spring 71 to be converted into a downward force acting in the direction P so that the loading force on the magnetic head 32 remains substantially constant irrespective of small vertical displacements of the head in relation to the carrier 21. Furthermore slight vertical movements of the carrier 21, due for instance to the latter being knocked, do not cause the magnetic sound head 32 to be lifted clear of the magnetic recording medium since the parallelogram guiding means comprising the struts 66 and 67 on the one hand, and the clamping means 54 and the lug 60 on the other, allow a resilient vertical floating movement of the magnetic sound head. Vertical movements of the magnetic sound head 32 are not accompanied by any radial movement, that is to say movement towards and away from the axis of rotation of the carrier 21. Once the gap 32a of the head 32 has been set for satisfactory engagement with the magnetic recording medium, vertical displacements of the recording medium during rotation of the turntable and consequent vertical movements of the recording head will not cause the gap 32a to come out of its correct position in relation to the recording medium.

A principal advantage of the mounting means 31 in accordance with the invention resides in the simplicity of making a precise adjustment of the position ofthe sound head. Adjustment is best explained with reference to FIG. 12 which shows the adjusting end of the holding means in accordance with the invention, that is to say at a position adjacent to the part 58 with the adjustment lug 60 attached to it. In order to adjust the position of the holding means and therefore of the magnetic sound head precisely with respect to the surface of the magnetic recording medium, that is to say for setting so as to insure that the axis B passing centrally through the sound head gap 32a is substantially upright in relation to the surface of the magnetic recording medium, it is only necessary to bring about a suitable tilting or twisting of the lug 60 about the axis X-X' indicated in FIG. 12, that is to say about the axis passing through the connecting part 61 attached to the part 58; this can be carried out with a simple slotted key 72 whose slotted end is passed through the slot 70 in the strut 66 in such a manner that the parts of the key on each side of the slot in the key fit around the lug 60 so that on making a suitable slight twisting movement of the key 72 in the plane indicated by the double arrow 73 is possible to make a precise fine adjustment of the position of the sound head 32 in relation to the recording medium surface. This is because the two parallel struts 66 and 67 make the forked part 54 move as the lug 60 is moved. Since the adjustment which is brought about to cause a change in position of the sound head is carried out at a position removed from the sound head itself, that is to say at the adjustment lug 60, which is connected with the sound head by the two parallel struts, the action of adjustment is not associated with a direct transmission of force to the magnetic head itself. It should more particularly be noted that any substantial influence on the thrust of the magnetic head against the recording medium is avoided so that there is no interference with electrical checking of adjustment as is usually carried out. A slight bending of the part 58 in the plane indicated by the double arrow 73 also brings about an adjustment in the position of the head 32 about the longitudinal axis, that is to say a swinging in the plane containing the axis B.

The adjustable magnetic head holding means in accordance with the present invention is not limited to telephone-answering machines using pieces of recording medium in a disc shape but can also be used with those having a cylindrical shape.

MODE OF OPERATION OF THE INVENTION The following description of the mode of operation of the telephone-answering machine in accordance with the invention is now made with more particular reference to the circuit diagram of FIG. 13, which is of a simplified character, taken in conjunction with the diagram of connections made and interrupted during rotation of the control disc 37 with its cooperating brushes.

As can be seen from the circuit diagram of FIG. 13, the telephone-answering machine comprises a power pack 75 whose input is connected via the line switch S1 (denoted by reference numeral 3 in FIG. 1) with the line voltage. The output of the power pack is connected with an output lead 76 supplying a DC voltage for the various components of the circuit. The power pack also supplies a drive AC voltage of 42 v. for the drive motor M (denoted by reference numeral 23 in FIG. 2) of the drive, it also supplies an AC voltage of 18 v. for energizing the erase head LK (denoted by reference numeral 30 in FIG. 2).

The circuit further comprises a record and playback amplifier 77, a HF premagnetizing voltage generator; a call circuit 79; a telephone transfer means Tr through which the connection with the telephone lines a and b is made. In the circuit diagram S2 is used to denote the switch for setting the operational state (denoted by reference numeral 12 in FIG. 2). As previously indicated the switch S2 has three different positions: a, message record; b, message playback for checking; and c, telephone operation. The microphone Mi with the switch-on button is shown in the connected position in the circuit diagram. The circuit further includes a call relay AR and a switching over relay AH. Reference numerals ml to m7 denote the operation of contact paths as controlled by the disc 37. These contact paths are as follows:

ml serves for holding the relay AR;

m2 serves for switching over the amplifier;

m3 serves for bringing about erasure (only when the apparatus is set for recording);

m4 serves for connecting the relay AH and the amplifier.

The paths m5 to m7 are only used in telephone communication systems in which a recorder coupler is required, as in the United States for America. The path m7 serves for separating the call sign in the case of United States four conductor systems (ring-up systems). Each path comprises two brushes and a corresponding track on the timing disc 37. g 1. Record Operation For this, the switch S2 is turned into the position a (record) in which the microphone is connected with the input of the amplifier.

INITIATION OF RECORDING By actuating the microphone button St the contact path ml which is initially open is bypassed so that the call circuit 79 is energized. This causes the call relay AR operate. The relay contact ar2 starts the drive motor M (denoted by reference numeral 23 in FIG. 3). The relay contact arl actuates the solenoid RM (denoted by reference numeral 27 in FIG. 2) so that the carrier 21 and the disc 37 are set in motion. The motion of the disc 37 causes the contact path ml to be closed (as shown in FIG. 14) so that the supply of current started by the original bypassing of the contact path ml is maintained for slightly less than one complete revolution of the disc 37.

AUTOMATIC ERASURE OF AN EARLIER RECORDING For the period of time in which the contact path m3, see FIG. 14, is closed the erase head LK (denoted by reference numeral 30 in FIG. 2) is connected with the AC voltage. The time of closure of the contact path m3 responsible of the erase head is so chosen as to correspond with one revolution of the magnetic recording medium carrier 21 so that there is a complete erasure of all further recorded messageson'the recording medium 21a.

1. Recording Message Ill.-.

For this the microphone Mi is connected with the input of the amplifier 77. The amplified NF voltage supplied by the amplifier is fed together with the premagnetizing signal from the HF generator 78 to the magnetic recording head TK (denoted by reference numeral 32 in FIG. 2).

Switching offat the end of the single rotation of the disc 37 is automatically brought about by the paths ml, m2 and m4. As already stated, the arrangement is such in the particular embodiment of the invention described that for a whole cycle the disc 37 makes a single revolution. For this single revolution the carrier 21 makes 16 revolutions in accordance with the ratio of the gear pinion pair connecting the carrier 21 with the disc 22.

2. Playback This serves for checking the message generator and is brought about by turning the switch S2 into the position b. The only difference between playback and record (a) operation is that the switch S2 in the position b connects the magnetic head TK with the input of the amplifier 77 while the microphone, which is adapted to act as a loudspeaker, is connected with the output of the amplifier. Furthermore, the premagnetizing generator or oscillator 78 is out of circuit.

3. Telephone Operation On bringing the switch S2 into the position 0 for this form of operation the output transformer Tr is connected with the telephone lines a and b.

The DC circuit of the telephone system is connected with capacitor C1 so that there is a high impedance for the incoming call signal (the high impedance circuit comprises the capacitor C1, the resistor R, the DC resistance of the transformer Tr and the inductance of the transformer). The incoming call signal passes via the transformer Tr and the contact path m2 to the call circuit 79 where it is rectified and, via a delay component, actuates the call relay AR.

Initiation of motion of the mechanical parts of the apparatus then occurs as was the case with the two previous forms of operation.

As soon as the path m2 has been switched over (see FIG. 14), the amplifier 77 is connected via the transformer Tr with the telephone lines a and b. After the closing of the contact track m4 via the energized relay AH the relay contact ah is connected with the secondary winding of the output transformer Tr so that the latter short-circuits the RC part of the circuit and the DC circuit of the telephone system is closed.

The recorded message is now played to the caller via the head TK through the amplifier 77 the output transformer Tr, and the telephone line.

END OF MESSAGE After the message has been played over to the caller, the message transmitting mechanism returns to the initial position, the contact path m serving for switching off. When the contact path ml is opened the relay AH is deenergized and the DC circuit of the telephone system is opened owing to the opening of the contact ah. The contact path m2 connects the transformer Tr with the call circuit 79 so that the telephoneanswering machine is-in a condition ready to respond to the next call.

FAILURE OF SUPPLY If the line voltage fails during a call the relay AH is deenergized so that the DC circuit is opened.

When the line voltage is later restored the motor 23 started again and rotates the disc 37 until the cycle'which was previously be started before the line supply was interrupted, is completed.

Various modifications can be made in the answering machine described. Thus, for instance, instead of providing knife edges at the ends of the struts 66 and 67 they can be provided with recesses for cooperation with. knife edges on lug 60 and the part 54.

Iclaim:

l. A telephone-answering machine comprising:

A. a-housing;

B. a chassis in the housing;

C. a magnetic recording device adapted to record a message and play it back to a telephone caller;

D. mechanical drive means for the recording device;

E. selective switching means for setting the apparatus in any one of the following operational conditions;

i. recording of the message;

ii. playback of the message for checking;

iii. telephone operation with playback of the message in response to a call; and

F. timing means for controlling the apparatus during at least one of the operational states;

G. a frame mounted upon the chassis, the magnetic recording device, the drive means and the timing means being mounted on the frame so as to form a single subassembly;

said recording device comprising a magnetic head unit, and open-ended resilient clamping means engaging said head;

two parallel generally horizontal struts, nonrigidly connected at one end of each thereof to the open end of said resilient clamping means, forming thereby hinged joints with the open end of the resilient clamping means;

an upright strut retainer carried by the frame, said retainer having a lug in deflection connection therewith, said struts having at opposite ends nonrigid connection to said retainer lug, forming thereby a parallelogram linkage whereby upon deflection of the lug a differential movement is imparted to the struts to achieve upright positioning of the head.

2. Apparatus according to claim 1 wherein the respective resilient clamping means and retainer lug are urged into connection by a diagonally disposed tension spring connecting the clamping means and retainer across the parallelogram linkage, urging the magnetic head in a direction which is generally perpendicular to the struts.

3. A telephone-answering machine comprising:

A. a housing;

B. a chassis in the housing;

C. a magnetic recording device adapted to record a message and play it back to a telephone caller;

D. mechanical drive means for the recording device;

E. selective switching means for setting the apparatus in any one of the following operational conditions;

(i) recording ofa message,

(ii) playback of the message for checking, and

(iii) telephone operation with playback of the message in response to a call; and

F. timing means for controlling the apparatus during at least one of the operational states;

G. a frame mounted upon the chassis, the magnetic recording device, the drive means and the timing means being mounted on the frame so as to form a single subassembly,

said frame comprising a casting mounted on the chassis of the apparatus, the subassembly comprising: first, second and third shafts mounted in the frame with an interference fit; a drive motor with a drive shaft; a disc-shaped magnetic recording medium carrierjournaled on the first shaft, the carrier being adapted to be driven by frictional contact at its periphery; magnetic recording medium mounted on the carrier; a pivoting lever; a large frictional wheel and a small frictional wheel, a shaft on which the large and small frictional wheels are mounted, this shaft being journaled in the pivoting lever; a solenoid for moving the pivoting lever and the large and small frictional wheels between an idle position, and a position in which the small frictional wheel makes peripheral contact with the periphery of the magnetic recording medium carrier and the large frictional wheel makes peripheral contact with the shaft of the motor, an indicator disc; peripheral marking in the form of a scale on the indicator disc, an opening being provided in the housing for viewing the scale, the scale indicating the course of a cycle of operation of the telephone answering machine; a rotary timing disc; metallic contact tracks on the disc, stationary brush means for makin contact with the tracks for closing and openlng electrrca contact paths on operation of the timing disc, the timing disc being connected with the indicator disc for rotation with it about a common axis at the same speed; and stepdown toothed gearing for causing the indicator disc to rotate with the magnetic recording medium carrier but at a lower speed.

4. A machine in accordance with claim 3 in which the ratio of the stepdown toothed gearing is such that for a number of revolutions of the magnetic recording medium carrier corresponding to playback from all available storage capacity of the magnetic recording medium the indicator disc makes substantially one single revolution.

5. A machine in accordance with claim 3 in which the magnetic recording medium is in the form ofa circular sheet of foil and the magnetic recording medium carrier has a resilient surface covering on which the magnetic recording medium rests loosely.

6. A machine in accordance with claim 5 in which the resilient surface covering of the magnetic recording medium carrier stops short of a central part of the magnetic recording medium carrier.

7. A machine in accordance with claim 5 in which the magnetic recording medium carrier comprises: a hub journaled on the first shaft; a radial turntable fixed on the hub; and the resilient covering extending partially over the turntable.

8. A machine in accordance with claim 6 in which there is an annular recess surrounding the flange leaving the surface of the turntable free.

9. A machine in accordance with claim 7 comprising a magnetic head which is arranged to cooperate with the magnetic recording medium, and driving engagement means arranged diametrically opposite the magnetic head.

10. A machine in accordance with claim 7 comprising a flange on the hub, the radial turntable being fixed on the undersurface of this flange, some of the resilient material covering being on top of the turntable and having an upper surface substantially flush with a top surface of the flange.

11. A machine in accordance with claim 10 comprising releasable means for holding the central part of the magnetic recording medium down against the flange.

12. A machine in accordance with claim 10 in which the turntable is covered on its undersurface by the resilient covering as well as on its top surface. 

1. A telephone-answering machine comprising: A. a housing; B. a chassis in the housing; C. a magnetic recording device adapted to record a message and play it back to a telephone caller; D. mechanical drive means for the recording device; E. selective switching means for setting the apparatus in any one of the following operational conditions; i. recording of the message; ii. playback of the message for checking; iii. telephone operation with playback of the message in response to a call; and F. timing means for controlling the apparatus during at least one of the operational states; G. a frame mounted upon the chassis, the magnetic recording device, the drive means and the timing means being mounted on the frame so as to form a single subassembly; said recording device comprising a magnetic head unit, and openendeD resilient clamping means engaging said head; two parallel generally horizontal struts, nonrigidly connected at one end of each thereof to the open end of said resilient clamping means, forming thereby hinged joints with the open end of the resilient clamping means; an upright strut retainer carried by the frame, said retainer having a lug in deflection connection therewith, said struts having at opposite ends nonrigid connection to said retainer lug, forming thereby a parallelogram linkage whereby upon deflection of the lug a differential movement is imparted to the struts to achieve upright positioning of the head.
 2. Apparatus according to claim 1 wherein the respective resilient clamping means and retainer lug are urged into connection by a diagonally disposed tension spring connecting the clamping means and retainer across the parallelogram linkage, urging the magnetic head in a direction which is generally perpendicular to the struts.
 3. A telephone-answering machine comprising: A. a housing; B. a chassis in the housing; C. a magnetic recording device adapted to record a message and play it back to a telephone caller; D. mechanical drive means for the recording device; E. selective switching means for setting the apparatus in any one of the following operational conditions; (i) recording of a message, (ii) playback of the message for checking, and (iii) telephone operation with playback of the message in response to a call; and F. timing means for controlling the apparatus during at least one of the operational states; G. a frame mounted upon the chassis, the magnetic recording device, the drive means and the timing means being mounted on the frame so as to form a single subassembly, said frame comprising a casting mounted on the chassis of the apparatus, the subassembly comprising: first, second and third shafts mounted in the frame with an interference fit; a drive motor with a drive shaft; a disc-shaped magnetic recording medium carrier journaled on the first shaft, the carrier being adapted to be driven by frictional contact at its periphery; magnetic recording medium mounted on the carrier; a pivoting lever; a large frictional wheel and a small frictional wheel, a shaft on which the large and small frictional wheels are mounted, this shaft being journaled in the pivoting lever; a solenoid for moving the pivoting lever and the large and small frictional wheels between an idle position, and a position in which the small frictional wheel makes peripheral contact with the periphery of the magnetic recording medium carrier and the large frictional wheel makes peripheral contact with the shaft of the motor, an indicator disc; peripheral marking in the form of a scale on the indicator disc, an opening being provided in the housing for viewing the scale, the scale indicating the course of a cycle of operation of the telephone answering machine; a rotary timing disc; metallic contact tracks on the disc, stationary brush means for making contact with the tracks for closing and opening electrical contact paths on operation of the timing disc, the timing disc being connected with the indicator disc for rotation with it about a common axis at the same speed; and stepdown toothed gearing for causing the indicator disc to rotate with the magnetic recording medium carrier but at a lower speed.
 4. A machine in accordance with claim 3 in which the ratio of the stepdown toothed gearing is such that for a number of revolutions of the magnetic recording medium carrier corresponding to playback from all available storage capacity of the magnetic recording medium the indicator disc makes substantially one single revolution.
 5. A machine in accordance with claim 3 in which the magnetic recording medium is in the form of a circular sheet of foil and the magnetic recording medium carrier has a resilient surface covering on which the magnetic recording medium rests loosely.
 6. A machine in accordaNce with claim 5 in which the resilient surface covering of the magnetic recording medium carrier stops short of a central part of the magnetic recording medium carrier.
 7. A machine in accordance with claim 5 in which the magnetic recording medium carrier comprises: a hub journaled on the first shaft; a radial turntable fixed on the hub; and the resilient covering extending partially over the turntable.
 8. A machine in accordance with claim 6 in which there is an annular recess surrounding the flange leaving the surface of the turntable free.
 9. A machine in accordance with claim 7 comprising a magnetic head which is arranged to cooperate with the magnetic recording medium, and driving engagement means arranged diametrically opposite the magnetic head.
 10. A machine in accordance with claim 7 comprising a flange on the hub, the radial turntable being fixed on the undersurface of this flange, some of the resilient material covering being on top of the turntable and having an upper surface substantially flush with a top surface of the flange.
 11. A machine in accordance with claim 10 comprising releasable means for holding the central part of the magnetic recording medium down against the flange.
 12. A machine in accordance with claim 10 in which the turntable is covered on its undersurface by the resilient covering as well as on its top surface. 